1. Field of the Invention
The present invention relates to a pin connector, a holder for holding such a pin connector, and an electronic component packaging board for mounting an electronic component thereon, and more particularly to the structure of an electronic component packaging board suitable for mounting thereon an electronic component such as a device socket by which a semiconductor device can detachably be supported.
2. Description of the Related Art
It has heretofore been well known in the art to mount a device socket by which a semiconductor device can detachably be supported, on a packaging board in a semiconductor device testing apparatus for measuring operating conditions of the semiconductor device supported by the device socket.
FIG. 1 of the accompanying drawings shows a conventional electronic component packaging board for soldering an electronic component thereto. As shown in FIG. 1, a packaging board 1 has a plurality of through holes 4 for inserting therein external leads 3 of a device socket 2 as an electronic component. When the external leads 3 are inserted into the through holes 4 and soldered thereto, the device socket 2 is electrically connected to patterns on the packaging board 1. The device socket 2 supports a semiconductor device 5 thereon which has external leads electrically connected respectively to the external leads 3 by contact elements 6.
FIG. 2(a) of the accompanying drawings shows another conventional electronic component packaging board to which an electronic component is detachably attached. FIG. 2(b) of the accompanying drawings is an enlarged fragmentary cross-sectional view of a small-size socket on the conventional electronic component packaging board shown in FIG. 2(a), and FIG. 2(c) of the accompanying drawings is an enlarged fragmentary cross-sectional view of another small-size socket which may be used on the conventional electronic component packaging board. Although not shown in FIGS. 2(b) and 2(c), the conventional electronic component packaging board shown in FIG. 2(a) has a plurality of small-size sockets.
As shown in FIG. 2(a), an electronic component packaging board 7 has a plurality of through holes defined therein at positions in alignment with external leads 3 of a device socket 2, and a plurality of small-size sockets 8 inserted and secured in the respective through holes. The electronic component packaging board 7 allows the device socket 2 to be electrically connected to patterns on the electronic component packaging board 7 simply when the external leads 3 are inserted into the respective small-size sockets 8. The inserted external leads 3 can easily be pulled out of the respective small-size sockets 8.
As shown in FIG. 2(b), each of the small-size sockets 8 comprises a tubular sleeve 10 inserted in a through hole 9 defined in the electronic component packaging board 7 and a contact 11 mounted in the tubular sleeve 10 for exerting resilient forces radially of the tubular sleeve 10. As shown in FIG. 2(c), each of the small-size sockets 8 may comprise a tubular sleeve 10 having a tip end portion inserted in the through hole 9 defined in the electronic component packaging board 7 and having an outside diameter greater than the outside diameter of a portion of the tubular sleeve 10 which houses a contact 11 therein. The portion of the tubular sleeve 10 which houses the contact 11 therein projects largely from the electronic component packaging board 7.
The electronic component packaging board 7 shown in FIGS. 2(a) through 2(c) suffers the following disadvantages:
If each of the small-size sockets 8 for holding the device socket 2 detachably is of the structure shown in FIG. 2(b), then the spacing between the small-size sockets 8 on the electronic component packaging board 7 cannot be reduced because of required distances to be kept between adjacent ones of the through holes. Reducing the spacing between the small-size sockets 8 requires the diameter of the sleeve 10 to be reduced, but there is a certain limitation on the reduction of the diameter of the external leads 3 which are inserted in the sleeves 10. The structure shown in FIG. 2(b), therefore, does not permit the external leads of an electronic component for use on the device socket 2 to be reduced in pitch.
On the other hand, if each of the small-size sockets 8 for holding the device socket 2 replaceably is of the structure shown in FIG. 2(c), then it is possible to reduce the diameter of the through holes for inserting the small-size sockets 8 therein. The reduced diameter of the through holes allows the adjacent small-size sockets 8 to be positioned closely to each other, so that the small-size sockets 8 can be spaced closely on the electronic component packaging board 7. However, since the portion of the tubular sleeve 10 which houses the contact 11 therein projects largely from the electronic component packaging board 7, the distance over which the external leads 3 of the device socket 2 are electrically connected to the through holes in the electronic component packaging board 7 is large.